Propeller



L. J. KOCH Aug. 30, 1932.

PROPELLER Filed Jan. 9, 1931 2 Sheets-Sheet Aug. 30, 1932. J. KOCH1,874,545

PROPELLER Filed Jan. 9, 1931 2 Sheets-Sheet 2 l 1 CONVEX 4; r

CONVEX I I l CONCAVE Attorney Inventor Patented Aug. 30, 1932 UNITE LYNNJ. KOCH, OF ALLENTOWN, PEfi NSYLVANIA PROPELLER This invention relatesto certain new and useful improvements in propellers, and the primaryobject of this invention is to provide a propeller for use in propellinga marine vessel or an airship as may be found desirable.

A very important object of the present invention is to provide apropeller which is capable of great pulling efiect with minimum motorspeed.

A still further object of the invention is to provide a propeller ofsuch a form in construction to be hereinafter more fully described, aswill eliminate the spreading of water over the circumference of thepropeller wheel area.

A still further object of the invention is to provide a propellerincluding a plurality of sections each of which is a complete propellerin itself, and the sections so arranged as to create in operation, equalpressure to all the sections or parts thereof in parallel direction ofmotion for discharging an equal amount of water at the rear of each unitas is taken in by the unit at the forward end thereof such a dischargebeing parallel throughout.

A still further object of the invention is to provide a propeller of theabove mentioned character, and wherein each unit is of such aconstruction as to provide for an equal strain throughout the entireunit.

Other objects and advantages of the invention will become apparent froma study of the following description, taken in connection with theaccompanying drawings where- Figure 1 is a side elevational view of asectional propeller, showing the same as applieo to a marine vessel.

Figure 2 is an end elevational view of the propeller unit.

Figure 3 is a plan view thereof.

Figures 4 and 5 are transverse sectional views taken substantially onthe lines H and 5-5 respectively of Figure 2.

Figure 6 is an end view of the propell clearly illustrating the relativepositions of the several units.

With reference more in detail to the drawings, it will be apparent thatthe propeller may be composed of any desired number of sections,respectively including a hub'having secured or formed integral therewiththe propeller blades 6. I

Each of the sections is provided with two blades extending oppositelyfrom the hub, and it is 'to be noted that theblades join the hubtangentially as shown, the roots or inner edges of the blade beingdiametrically oposite one another. The blades are 0 2 0 positely curvedlongitudinally and in the direction of rotation of the propeller, thefront surfaces of the blades being concave, and the rear surfaces beingconvened.

The leadingedges 9 of the blades are concaved, and the rear or trailingedges 10 convex. Each blade increases in width from the root 40f theblade to the outer end or. tip of the blade, the forward or leadingedge-9 of the blade being curved a greater degree than the trailing orrear edge 10 of the blade so that as will be noted, the blades are ofgreater wic th adjacent their tips than adjacent the roots ofthe'blades.

The cutting or leading edge 9 of each blade is brought to an edge bybeveling away the material from the front or convex side 7 as at-llinstead of from the rear or concaved side 8 of the blade. r

Adjacent its trailing edge each blade. is beveled on its concave or rearside -8 as at 12. Each of said blades at its root 4.- so joins the hubof the propeller that the blades extend from the hub obliquely to theaxes of the hub with the leading edge of the blade at the root 4terminating flush with the forward end of the hub, and the trailing edgeof said root terminating flush with the rear end of the hub,-tl1eleading and trailing edges respectively of the blades springing from thehub at said roots tangential to the hub.

In Figure. 1 I have shown the propeller wheel-as applied to .a marinevessel designated generally 'by the reference character V. In thisinstance the propeller wheel 'consists of two of such sections hereindescribed in detail the said sections being suitably keyed to thepropeller shaft S. In Figure 6 I have shown the propeller wheel asconsisting of three of such sections, and as is s'rares PATENT OFF CEapparent, irrespective of the number of sections to be used, it will benoted that when the sections are assembled on the propeller shaft S,each unit is set a fraction of a turn relative to the next precedingunit so that the blades extend fanwise from diametrically opposite sidesof the shaft Sso that the concave surtfaces confer-into a continuousrotary surface as shown.

The concave surfaces providing the propolling surface for the propeller,it will 'be apparent that when the fluid element is gathered in by theblades, it will be forced not only rearwardly but also inwardly towardthe axes of the propeller, the hollow sides of the blades holding thewater in circumferonce or pipeline formation thereby delivering-the fullforce of water against the rear body of water by each unit instead ofonly part of the water being held to the rear, and the remaining partbeing forced radially outwardly toward the circumference of the wheel. Y

A still further advantage of an invention of thischaracter will 'be,that when not inuse, the sections may be readily stored, and furthenlthat in the event of breakage 'to oneofthe'units, the same may be replacedwith facility.

It will be also noted that each propeller section is a unit in itselfindependent of the remaining sections'of the propeller, and that theadditi'on'or removal of one or more sections will not weaken theremaining sections of the propeller; further the number ofsectionscontituting the propeller maybe varied at will. I

:In making the propeller sectional, and each section or unit beingpractically an exact replica of the othersection, eliminates expensiveindividual patterns and reduces cost 7 of manufacture.

Even though I have herein shown and described the preferred'enibodimentof the in- Wention, it is to be understood that'the same is susceptibleof changes, modifications and improvements coming within the scope ofthe appended claim.

Havingfthus described my invention, what claim as new is: p r

A propeller comprising-a :pluralityof units hvingfhubs'and oppositelyprojecting blades secured toLthe hub and having the inner portionsthereof overlapping, said blades being longitudinally curved inoppositedirections,

theiblndesoncorresponding sides of the hubs baiiag soarranged relativeto one another as to extend fanwise from the propeller shaftwith-thertips of the blade-edge to edge. I

testimony whereof I aflix my signa- LYNN J. KOCH.

